Thirty asymptomatic men and 19 asymptomatic women were monitored during one night's sleep to determine the incidence of breathing abnormalities and oxygen desaturation in normal subjects. Twenty men accounted for 264 episodes of nocturnal oxygen desaturation or abnormal breathing. Women never experienced oxygen desaturation, and only three had a total of nine episodes of apnea. These sex differences were highly significant (P less than 0.003). In men, increasing age and obesity correlated positively with the incidence of nocturnal oxygen desaturation and abnormal breathing. Four asymptomatic men weighing more than 90 kg dropped their saturation to very low levels (68 to 72 per cent). Abnormal breathing and oxygen desaturation during sleep in subjects with chronic obstructive lung disease of the syndrome of hypersomnolence with periodic breathing may represent the superimposition of smoking or obesity on a normal tendency to snoring and oxygen desaturation in men.

Sleep apnea, hypopnea and oxygen desaturation in normal subjects. A strong male predominance.

The Hoffmann reflex: a means of assessing spinal reflex excitability and its descending control in man.

1. The EMG sequence activated before the initiation of a number of fast forward-oriented voluntary movements was analysed quantitatively in normal subjects. 2. The sequence consisted of an initial inhibitory component directed to the soleus motor nucleus, followed by a second excitatory one directed to the tibialis anterior (TA). 3. The spectrum of functional utilization included motor tasks in which the prime movers are leg and thigh muscles (initiation of gait, rising on tip-toes), thigh and trunk muscles (fast-forward bending of the trunk, standing up) and upper-limb muscles (forward throw or catch). 4. In a same motor task and across the different motor tasks, performed at various speeds, the latency of soleus inhibition and TA activation with respect to the onset of movement co-varied according to a linear function, indicating a close temporal correlation between the two components. 5. In all the movements investigated, the earliest mechanical effect was a backward displacement of the centre of foot pressure in the sagittal plane. 6. Soleus inhibition alone and TA burst alone were each able to produce a backward displacement of the centre of foot pressure, but the effect was significantly slower after soleus inhibition. 7. The spatio-temporal parameters of the sequence were modulated according to the pre-existing postural conditions. For the gait initiation protocol, increasing initial forward leaning led to a decrease in the amplitude of soleus inhibition and the TA burst, and to a change in their relative time delays. Modulation was different on the two sides. We could define a postural boundary as the degree of forward leaning beyond which the full sequence is no longer called into action. 8. The spatio-temporal parameters of the sequence were pre-set according to the requirements of the forthcoming movement. In the gait initiation protocol, the amplitude and synchronization of the TA burst were directly correlated with velocity of movement, while the relative delay between soleus inhibition and TA activation was inversely correlated. Modulation on the two sides differed. We could define a velocity boundary as the velocity of movement below which the full sequence is no longer called into action. 9. We suggest that the EMG sequence described can be considered a motor programme that, through direct action on the position of the centre of foot pressure (the variable primarily controlled), will precisely adjust the configuration of forces external to the body, allowing the contraction of the prime mover(s) to interact appropriately with them for the production of a specific, forward-oriented movement.

A motor programme for the initiation of forward-oriented movements in humans.

1. General methodology 2. Monosynaptic Ia excitation and post-activation depression 3. Muscle spindles and fusimotor drive: microneurography and other techniques 4. Recurrent inhibition 5. Reciprocal Ia inhibition 6. Ib pathways 7. Group Ii pathways 8. Presynaptic inhibition of Ia terminals 9. Cutaneomuscular, withdrawal and flexor reflex afferent responses 10. Propriospinal relay for descending motor commands 11. Involvement of spinal pathways in different motor tasks 12. The pathophysiology of spasticity and parkinsonian rigidity.

The Circuitry of the Human Spinal Cord : Its Role in Motor Control and Movement Disorders

Sleep and quantitative EEG in neurodegenerative disorders

• A common pattern of reduction in both rapid eye movement and non—rapid eye movement sleep associated with various lateral gaze paralyses was present in four cases of brain-stem stroke. From computed tomographic scan data, clinical inferences, and, in two cases, neuropathologic sections, the common lesions were localized in the medial pontine tegmentum, ie, the inner part of the gigantocellular and pontis centralis caudalis nuclei. These data in humans were compared with lesions obtained experimentally in cats.

A Syndrome of REM and Non-REM Sleep Reduction and Lateral Gaze Paresis After Medial Tegmental Pontine Stroke: Computed Tomographic Scans and Anatomical Correlations in Four Patients

H.P Cathala

Papers

A Syndrome of REM and Non-REM Sleep Reduction and Lateral Gaze Paresis After Medial Tegmental Pontine Stroke: Computed Tomographic Scans and Anatomical Correlations in Four Patients

Effect of voluntary contraction on H reflex changes induced by cutaneous stimulation in normal man.

Sleep respiratory arrhythmias in control subjects, narcoleptics and non-cataplectic hypersomniacs.

Enregistrements polygraphiques nocturnes dans trois cas de maladie de Creutzfeldt-Jakob

Human sleep and 5-HTP. Effects of repeated high doses and of association with benserazide (RO.04.4602)